8 Liter; One size fits most; Includes 750mL flask and hose; Front: 5mm foam shoulder strap for comfort; Expandable zippered phone pocket; Removable Strap for left or right wearing; Additional run strap (with clip) removable when not using for running - built for a bounce free run; Back: two side stash Pockets; Small zipper stash pocket, lined with brushed tricot, for sunglasses or phone; Main zipper storage pocket with internal bladder pocket; Mesh back panel for breathability; Weight with flask: 10oz/283g; Weight w/o flask: 8oz/227g